How do I enable Application Insights server telemetry on WebApi project that uses OWIN?

Question

We are having a bunch of problems (read long response times) with a couple of projects in production and wanted to see exactly what was happening on the server. I then proceeded

Answer 1

Below is our implementation of a OWIN Middleware for Application Insights.

/// 

/// Extensions to help adding middleware to the OWIN pipeline
/// 
public static class OwinExtensions
{
    /// 

    /// Add Application Insight Request Tracking to the OWIN pipeline
    /// 
    /// 
    public static void UseApplicationInsights(this IAppBuilder app) => app.Use(typeof(ApplicationInsights));

}

/// 

/// Allows for tracking requests via Application Insight
/// 
public class ApplicationInsights : OwinMiddleware
{

    /// 

    /// Allows for tracking requests via Application Insight
    /// 
    /// 
    public ApplicationInsights(OwinMiddleware next) : base(next)
    {
    }

    /// 

    /// Tracks the request and sends telemetry to application insights
    /// 
    /// 
    /// 
    public override async Task Invoke(IOwinContext context)
    {
        // Start Time Tracking
        var sw = new Stopwatch();
        var startTime = DateTimeOffset.Now;
        sw.Start();

        await Next.Invoke(context);

        // Send tracking to AI on request completion
        sw.Stop();

        var request = new RequestTelemetry(
            name: context.Request.Path.Value,
            startTime: startTime,
            duration: sw.Elapsed,
            responseCode: context.Response.StatusCode.ToString(),
            success: context.Response.StatusCode >= 200 && context.Response.StatusCode < 300
            )
        {
            Url = context.Request.Uri,
            HttpMethod = context.Request.Method
        };

        var client = new TelemetryClient();
        client.TrackRequest(request);

    }
}